Risk Factors for the Progression of Diabetic Retinopathy after Cataract Surgery

To assess the effect of cataract surgery on diabetic retinopathy(DR)and to identify the risk factors for the postoperative progression of DR, we reviewed the medical records of 214 diabetic patients who had undergone cataract surgery from August 1997 to November 1998.Out of total 274 eyes, 58 eyes(19.6%)showed progression of DR by one or more grades in ETDRS classification after cataract surgery. One hundred fifty eyes(56.9%) achieved postoperative visual acuity of 0.5 or better and 214 eyes(78.1%) showed an improvement in visual acuity by two lines or more. Compared with non-progression group, progression group showed statistically significant decrease in postoperative visual acuity. Preoperative severity of DR, glucose control with insulin, and the presence of postoperative macular edema within 3 months were identified as significant risk factors to progress DR. Operative method, intraocular lens position or intraoperative posterior capsular tear did not seem to contribute to the progression of DR. In conclusion, the severity of DR and the status of glucose control at the time of cataract surgery were highly correlated with the postoperative progression of DR.

The Expression of ICAM-1 by Cytokines and the Effect of Dexamethasone on ICAM-1 Expression in Cultured Keratocytes

Intercellular adhesion molecule-1 (ICAM-1) Is a cell-surface glycoprotein that may regulate leukocyte-endothelial adhesion, leukocyte migration into the tissues, and leukocyte trafficking with target cells during inflammation and immune responses. Expression of ICAM-1 have been observed in diseased cornea, and it has been reported that expression on corneal cells is increased in the presence of pro-inflammatory cytokines. We investigated expression of ICAM-1 by various cytokines on cultured rabbit keratocytes and effect of dexamethasone on cytokine-induced ICAM 1 expression, using an ELISA technique. Cultured rabbit keratocytes were incubated for 24hrs with INF-gamma 10ng/ml, TNF-alpha 10ng/ml IL-1beta 5ng/ml, TGF beta 5ng/ml, with or without 0.1micromiter Dexamethasone. Rabbit keratocytes treated with cytokine or dexamethasone were incubated with antral-ICAM-1 for 15 hours. Expression of ICAM-1 was measured with ELISA technique. As a result, expression of ICAM-1 was increased in rabbit keratocytes stimulated with INF-gamma, TNF-alpha, TGF-beta, not IL-1beta, and dexamethasone inhibited expression of ICAM-1 in cells stimulated with INF-gamma, TNF-alpha. This results are helpful to understand the role of ICAM-1 in the pathophysiology of inflammatory corneal diseases and the action mechanism of glucocorticosteroids. Further study about expression of ICAM-1 and their regulation & modulation may lead to new therapies in treating inflammatory corneal diseases.

Evaluation of New Viscoelatics in Rabbit: Healon, Healon GV, Provisc

Viscoelastic substance which is one of the most important thing in anterior segment surgery sells many kinds as to its unique properties. The complications during its use are acute postoperative intraocular pressure elevation, corneal edema, severe ocular pain, blurred vision. The extent of elevation, peak time and normalized time of intraocular pressure can be varied by operative technique, amount of residual viscoelastics in anterior chamber, kinds of viscoelastics. To compare the safety of Healon GV and Provisc with Healon, we injected the same amount of those three viscoelastics into anterior chamber of 27 rabbits divided by three groups and examined the degree and change of intraocular pressure elevation, corneal edema, intraocular inflammation, maintenance of anterior chamber. Healon GV showed the persistent intraocular pressure elevation immediately after injection and normalized at 24 hours. Healon and Provisc showed elevated pressure at 7 and 5 hour but normalized within 12 hour. Corneal thickness increased significantly at 1 to 7 hour in Healon and Healon GV group and continued to 24 hour in Healon GV group and there was no significant pressure change in Provisc group compared with preinjection status. There were no significant differences in intraocular inflammation, amintenance of anterior chamber between three viscoelastics. Healon GV shoed more frequent, higher intraocular pressure elevation as compared to the other two viscoelastics, but pressure was normalized within 24 hour. From the above results, it is concluded that Healon GV can be used well with caution and Provisc can be used widespreadly due to its minor complication, too.